1. Field of the Invention
The invention is in the field of non-perverting single surface reflecting mirrors.
2. Description of the Prior Art
Most mirrors used today such as plane, convex, concave and parabolic mirrors give perverted images i.e., the image of a right hand is a left hand, images of words are backwards, and so forth. It is possible to obtain non-perverted images by utilizing two plane mirrors at right angles to effect a double reflection. Two successive image-perversions combine to produce a non-perverted image. An example of such a technique is shown in U.S. Pat. No. 1,991,054 to Hampke.
A non-perverted image may also be formed with a concave cylindrical mirror. Such a cylindrical mirror consists of a single reflecting surface and is referred to in classic literature of Plato and Lucretius, and is described in modern works such as Mathematical Puzzles and Diversions, by Martin Gardner, Simon and Schuster, New York (1959).
It is desirable to provide a non-perverted single surface mirror which gives a true image of the object under observation. The disadvantage of the prior art non-perverted concave cylindrical surface is the large image distortion present resulting from elongation of the image in the direction of the cylindrical axis. An additional problem with the concave cylindrical mirror is its poor image focusing ability inasmuch as cylindrical rather than spherical wavefronts are generated.